In many semiconductor arrangements, two semiconductor switches are connected in series thereby forming a half bridge. One, two, three or more of such half bridges can be used in power supplies for motors, in rectifiers, power converters etc.
In a half bridge, at least two controllable power semiconductor switches are connected in series. Between the two controllable power semiconductor switches, the series connection includes a circuit node. During operation, the series connection is connected to a supply voltage between a positive and a negative supply potential. The power semiconductor switch that is electrically connected to the negative supply potential is often referred to as “low side switch”. Accordingly, the power semiconductor switch that is electrically connected to the positive supply potential is often referred to as “high side switch”. During operation, the voltage at the circuit node alternates between two potentials which are substantially identical with the positive and negative supply potential.
In many conventional semiconductor arrangements, metallized ceramic substrates are used to realize at least some of the electrical connections of the arrangement. The power semiconductor switches are arranged on the top side of the substrate. The bottom side may be thermally and electrically coupled to a heat sink. In conjunction with the isolating ceramic, the metallizations of the ceramic substrates form a capacitance relative to a ground potential which is applied to the heat sink. Depending on the amplitude and frequency of the alternating voltage at the circuit node, displacement currents occur that continuously charge and discharge that capacitance. Due to displacement currents in unavoidable inductivities of the arrangement, voltage drops over such inductivities may cause undesired EMI (electromagnetic interference).
In order to reduce the inductivities, the ceramic substrates may be designed as multilayer substrates with vias that electrically interconnect different metal layers of the substrate. The vias allow for short electrical connections with reduced impedance. However, ceramic multilayer substrates having vias in the ceramic are quite expensive.
Therefore, there is a need for a semiconductor arrangement having a low inductivity even without such vias in the ceramic.